This enzyme is an integral-membrane protein that carries out the second prenyltransfer reaction involved in the formation of polar membrane lipids in Archaea. Requires a divalent metal cation, such as Mg2+ or Mn2+, for activity [2]. 4-Hydroxybenzoate, 1,4-dihydroxy 2-naphthoate, homogentisate and alpha-glycerophosphate cannot act as prenyl-acceptor substrates [2]. The other enzymes involved in the biosynthesis of polar lipids in Archaea are EC 1.1.1.261 (sn-glycerol-1-phosphate dehydrogenase), EC 2.5.1.41 (phosphoglycerol geranylgeranyltransferase), which, together with this enzyme, alkylates the hydroxy groups of glycerol 1-phosphate to yield unsaturated archaetidic acid, which is acted upon by EC 2.7.7.67 (CDP-archaeol synthase) to form CDP-unsaturated archaeol. The final step in the pathway involves the addition of L-serine, with concomitant removal of CMP, leading to the production of unsaturated archaetidylserine [3]. Belongs in the UbiA prenyltransferase family [2].